Supplement
Boric acid
Vaginal boric acid, given as capsules or suppositories inserted at night, is a mild antiseptic used mostly when a vaginal thrush infection keeps coming back despite standard antifungal treatment. Among diabetic women whose infection was mainly caused by Candida glabrata, one randomized study found the yeast was cleared more often with boric acid than with a single dose of fluconazole, but other measures were similar. Its trials used antifungal drugs, not a dummy treatment, for comparison, and reports on bacterial vaginosis lack a comparison group. Swallowing boric acid is dangerous, so it belongs out of the reach of children, and it is not used during pregnancy.
Sources: PMID 17259500; PMID 21774671; PMID 33485927; PMID 34561373
- Updated
- How we grade
- Best evidence
- Grade C: limited evidence
What boric acid is good for
How we grade →Some evidence, still limited
Is boric acid safe?
Safety note. Talk to a doctor or pharmacist before you start boric acid if you take prescription medicines, are pregnant or breastfeeding, or have a long-term health condition. Supplements can interact with medicines.
Evidence by condition
- Strong
- Moderate
- Limited
- Very limited
CVulvovaginal Candidiasis (Yeast Infection)
▲ Candida glabrata Clearance1 outcome · 2 studies
Vulvovaginal Candidiasis (Yeast Infection): all the evidence on its own page
| Grade | Outcome | Effect | Size and studies |
|---|---|---|---|
| C | Candida glabrata ClearanceImprovementStudied as: Boric acid 600 mg vaginal suppositories, placed in the vagina once daily for 14 days (vaginal use only; boric acid is poisonous if swallowed), compared with one dose of the prescription antifungal fluconazole, in women with diabetes and a Candida glabrata vaginal yeast infection; cure was checked by culture on day 15. No placebo-controlled trial exists and no review rates the certainty.Studies that measured candida glabrata clearance (2 studies)
| Improves | 2 studiesReviewed |